Elevator equalizer



Sept. 18; 1934.

J. E. EVANS ELEVATOR EQUALIZER Filed July l, 1933 2 Sheets-Sheet 1 INVENTOR. Jar/w E. firm/a ATTORNEYS.

Sept. 18, 1934. EVANS 1,973,850

ELEVATOR EQUALI ZER Filed July 1, 1933 2 Sheets-Sheet 2 ATTORNEYJ lt'atented Sept. 18; I934 1,975,850 ELEVATOR EQUALIZE-R Joseph E. Evans, Bedford, Ind. I Application my 1, 1933, Serial N6. 678,605 I 1o oasi ((31. 187-1) This invention relates to a stress equalizing device which is particularlyuseful as an equalizer for the hoisting cables of an elevator but which maybe used as well for other purposes wherein it is desired to equalize the strain upon a plurality of cables or other members which are used for imparting a tractive or supporting force.

The principal object of the invention is to provide a simple and compact arrangement by which 7 l0 the strain on a large number of cables may be equalized. Heretofore, in order to equalizethe strain on a ;large number of elevator cables; it has been a common practice to use some arrangement of sheaves or pulleys; Where relatively large cablesare used, relatively large sheaves must also be used to prevent excessive bending stresses upon the cables passing over said-sheaves. The use of large sheaves results in a necessarily large distance between the parallel cables and a corresponding increase in size and expense of the overhead structure necessary to support the elevator. has been used for equalizing stresses but er'etofore such levers have been so arranged as to require as much orgreater'space between cables as with a sheave or pulley'arrangement.

In the present invention a lever type of equal-- izer is used andthe levers'are so positioned with respect toeach other as to occupy the least possible space while at the same timepermitting as much lever movement as is necessary for equalization of the stresses on the cables.

' Another feature ofthe invention resides in the provision of a novel arrangement of single-trees and trunnion blocks connected therewith. by

means 'of which a plurality of cables may be N :placed closely together and may still be readily accessible for adjustment. v Qthe'rpb'jects and features 01- the invention will be understood from the accompanying drawings and the following description and claims:

Fig. 1 is a side elevational view or a preferred 'iorm or the invention used for ,e'qualizing thestrain on six cables. Fig. 2 is an end elevational viewof the same partly in section. Fig. 3 is a sectionalplan 'view.taken on the line 3--3 oi Fig. 1. Fig. tie a similar section takenon the line H or Fig l. Fig. 5 is a plan view ot the linkage and leverage used in an alternative form ofthe invention. Fig; 6 is a side'elevational view of the same. Fig-7 is'a perspective view of one of the lever members used in the term of the invention shown in Figs. 5 and}. Fig. 8 is a side elevational view of a modification of the invention as used forsev'en, eight, nine or ten cables. 42

I Fig. 9 is a similar view oLanother modification used for twelve cables; V Fig. 10 is a perspective view of a support member ioryth e draw. head of an elevator used inthe iormoi inventionshown 0 in Figs.-1', 2, 3 and 4. Fig. 11 is a perspective invention shown in Fig. 8.

In many cases, a lever arran ement portions of mt support member 21 view of one of the members used in the form of arrangement or singletrees employed when the apparatus 0! Fig. 8' is used for ten cables.

In' Figs. 1, 2 .and 3 there is shown, by way of illustration, 9. pair of I-beams 20 constituting the draw head of an elevator The said I-beams rest upon a-support member 21 shown in detail in Fig.

Fig 12 shows the 10 and are.secured thereto by means of clamps 22 grasping the lower flanges of said I-beams. The

support member 21' is preferably provided with three vertically projecting and spaced-apart bear ing portions 23a,23b and 230 which may be secured thereto by means of bolts 24,.orwhich may be formed'integrally therewith as desired. A pin 25 is journaled in bearings 26 formed in the cen- 'tral bearing member 23b and one of the outer bearing members 2311. A similar pin 27 is journaled in bearings 28, one of which is formed in the central bearing member 23b and the other in the second outer bearing member 23c. A lever. 29 ispivotally mounted onthe pin 25 and a similar lever 30 is mounted upon the pin 2'7. "The said levers, as will be seen inthe drawings. extend through the spaces between the bearing and are are ranged side by side in a substantially parallel relation. The two levers are of substantially the same length and the pins 25 and 27 in the embodiment oi! the invention shown are offset in such position that the efiective length ot one arm of each lever is approximately twice that of the other arm of the same lever and the longer and shorter arms of the two levers are oppositely positioned.

To the short arm oi each oi';the levers 29 and 30 there is pivotally connected a draw bar 31 by means of apin 32. A link .33 is pivotally attached by means of a pin 34m the long arm of each of the levers 29 .and 30. 'Iihe links 33 are twisted as shown in Figs. 1 and-2 and are pivotally attached at their upper ends by pins 35 to opposite" ends, of an equalizing lever 36 extending diagonally across the two levers 29 and 30 preferably formed as a pair .of parallel 'bar's.. A third draw" bar 37fis pivotally attached by means of a pin 38 to the mid-pointer the lever 36.

The upper end of each of the draw bars 31 and B'Tpasses through an opening in a trunnion rot block 39 and is-.adjustably secured to said tnm-' Q nion block py'm'eans oilock nuts 40 threaded upon saiddrawbar and locked against the upper and lower surfaces 01 thetrunnion block. Each 41 uponwvhlch there is mounted a pair" of links forming a singletree'e Between the ends 01' the oi said trunnion blocks, carries a pair ottrunnions 1 whichpasses the lower'end of a cable terminal Q 44. 'The endsot said cableterminals are threaded and have mounted thereon lock nuts 45 engaging the upper and lower surfaces of said trunnion blocks. Each of said terminals has secured thereto in a well known manner a cable 46.

As will be apparent from the drawings, particularly Figs. 3 and 4, the particular arrangement of the levers 29 and 30 here shown permits the draw-bars 31 and 37 to be positioned as closely together as the necessary lengths of the levers 29 and 30 will permit. This is accomplished by the parallel, side-by-side relationship of the said levers and the fact that pivot pins 25 and 27 are supported independently of each other and are not coaxially arranged. It is also apparent that this particular position of the pivot pins causes the levers 29 and 30, together with the equalizing lever 36, to place an equal strain on each of the three draw-bars. It will also be seen that this arrangement of levers permits the two outer draw-bars to be offset from the axis of the drawhead so that the three draw-bars lie in a substantially straight, diagonal line.

Figs. 1 and 4, the singletrees 42 are arranged in substantially parallel relation to each other but at an acute angle to the axis of the drawhead 20. This latter fact, combined with the diagonal ar-. rahgement of the draw-bars themselves, makes each of the lock nuts 40 and 45 readily accessible for adjustment although the actual distance between the planes of the six cables as viewed in Fig. 1 is relatively small. It is this distance which largely determines the size, strength and cost of the overhead structure necessary to support and move an elevator of a given weight.

In Figs. 5, Sand 7, there is shown a modified form of the invention in which there is used a support member 121; similar to the member 21, upon which there is'pivotally mounted apair of levers 129 and 130 arranged in substantially the same manner as the levers 29 and 30 previously described. Each of said levers, however, has at the end of the long arm thereof an offset projection 47, said projections lying substantially on the center line between the levers 129 and 130 when assembled in the parallel side-by-side relation shown in Fig. 5. A draw-bar 137 has pivotally attached thereto by means of a pin 48 a pair of plates 49. Two links 50 are connected'by pivot pins51 to said plates and by pivot pins 52 to the offset projections 4'? of the levers 129 and 130. Draw-bars 131 are connected by pivot pins 53 to the short ends of the levers 129 and 130.

It will be seen that by this construction substantially the same result will be obtained as by thatv previously described.- The space requirements are the same and the three draw-bars are arranged in the same offset diagonal relation as in the previous construction, the stress thereon being equalized in the same manner. When singletrees are attached to the draw-bars as shown in Figs. 1 and 4 the said slngletrees may be arranged in the same manner as previously described to provide for the maximum accessibility for adjustment.

In Fig. 8 there. is shown a modification of the invention which permits the use of seven, eight, nine or ten cables. In this construction, reference numbers in the two hundred series refer to parts having similar construction and function to those indicated by corresponding reference numbers in the unit series in Figs. 1, 2, 3 and 4. The parallel companion levers 229 and 230 are pivotally mounted upon amember 54, the said member being shown in detail in Fig. 11. The said member has projecting spaced apart bearing portions 55a, 55b and 550 having bearing open- As shown in 'is possible for the necessary lever lengths.

ings 226 and 228 serving the same purpose as bearing openings 26 and 28. The member 54 also has downwardly projecting bearing extensions 56 having bearing openings 5'7 therein. Inthis construction, if the pins 225 and 22'7 are spaced to give a lever ratio of two to one, the strain applied to the member 54 at the bearings 57 will be equally distributed over the draw bars ,231 and 237.

The draw head 220 in this construction rests upon a support member 221 similar to the member 21, upon which there are mounted by means of pins 58 a pair of parallel companion levers 59. Each of'said levers has a draw-bar 60 attached to one end thereof and a link 61 is pivotally attached to the opposite end of each. The links 61 are pivotally connected to opposite ends of an equalizing lever 62 which is pivotally attached at its midpoint to member 54 by means of a pin 63 'journaled in the bearing openings 57.

When this construction is to be used for a tencable hoist, a singletree and a pair of cables are attached to each of the fivedraw-bars as shown in Fig. 12. The pins 58 are then positioned to give a three to two ratio to the levers, 59, the draw-bars 60 being attached to the long arms of said levers. The strain upon the five draw-bars and ten cables is then equally divided. When it is desired to use a nine-cable hoist with this arrangement, only a single cable is attached to. the draw-bar 227 while a singletree and two cables each are attached to the remaining draw-bars. The positions of the pins 225, 227 and 58 are then selected to provide the-proper distribution of stress to equalize the forces on the nine cables. 1111 For eight cables, a single cable is attached to each-of the draw-bars 60 and two cables each to the remaining draw-bars. Forseven cables, a single cable is attached to each of the draw-bars 60 and 237 and two cables to each of the draw bars 231. In eachcase, the appropriate location of pins 235 and 25B is selected to equalize the stress on the cables employed. In this manner an extremely flexible construction is provided which requires only a change in the location of the pivot pins to provide tor a variety of cable arrangements. At the same time, the construction is as compact as can be arranged and the draw-bars and cables lie as closely together as In Fig. 12, there is illustrated the arrangement of singlet'rees employed when the apparatus of Fig. 8 is used for ten cables. From this it will be apparent that the diagonal arrangement of the three central draw-bars is preserved as in Fig. 4 and the position of the two additional drawbars 601s such as not to interfere with the accessibility of the remaining draw-bars.

In Ffg. 9 there is shown a modification of the invention for use with twelve cables. In this construction the draw head 320 is carried upon support bearings 64 on which there is pivotally mounted an equal armed lever 65 by means of a pin 66. At each end of said lever there is connected a member 354 s milar in construction and I tion and function to parts designated by corresponding numbers of the unit series in-Figs. 1,

2, 3 and 4. In this construction it is apparent that the six' draw-bars are each carrying an equal stress and the singletrees may be-arranged thereon in the manner previously described to dissingletre'es is preserved at each side of the construction and the accessibility of the same for adjustment is preserved.

Several modifications of the invention have been descr'bed herein by way of illustration. Other modifications not departing from the scope of the invention as defined by the appended claims, will be apparent to persons skilled in the art to which the invention pertains. For example, chains or cables may be subst tuted for the links specifically shown in certain of the drawings, particularly links 33 and 50. The terms link and link-connected used in certain of the claims is intended to include such an equivalent modification. It is also possible to oflset the levers 29 and 30 to-place the draw-bars 31 and 3'7 upon the axis of the drawhead 20. Although the arrangement shown herein is preferable in the majority of installations since it preserves the maximum accessibility of the adjusting nuts, still the modification does not completely destroy the accessibil'ty and may be-necessary insome in-'- stallations. I

The invention claimed is:

1. A stress equalizing device including a support, a pair of levers pivotally mounted on sa'd support and placed side by side, an equalizing lever diagonally positioned with respect to said first mentioned levers and link-connected at one end to one end of one,of.said first ment'oned levers and at its opposite end to the opposite end of the other of said first mentioned levers, and draw-bars pivotally connected to the remaining ends of said first mentioned levers and intermediate to the ends of said equal'zing lever.

2. A stress equalizing device'including a support,-a pair of levers pivotally mounted on said support and placed side by side, an equalizing lever. diagonally pos'tioned with respect to said first mentioned levers and link-connected at one end to one end 0L one of said first mentioned levers and at its opposite endto the opposite end of the other of said first mentioned levers, drawbars pivotally connected to the remaining end of said first mentioned levers and intermediate to the ends of said equalizing lever, a singletree piv otally attached to each of said draw-bars, and a cable pivotally attached to each end of each of said singletrees.

3. A stress equ'alizingldevice including a support, a pa r of levers pivotally mounted on said support and placed side by side, a draw-bar pivotally attached to one end of one of said levers, a second draw-bar pivotally attached to the opposite end of the other of said levers, a third draw-\ I bar centrally positioned with respect to said first and second draw-bars, and means link-connecting sa'd third draw-bar to each or the remainin ends of said levers.

4. A stress equalizing device including a support, a pair of levers pivotally mounted on said support and placed side by side, a draw-bar pivotally attached to one end of oneof said levers, a

second draw-bar pivotally attached to the opposite end of the other of said levers, a third drawbar centrally positioned with respect to,said first 5. A stress equalizing device including a support [having three projecting bearing portions arranged side by side, a lever pivotally mounted between the central one of said portions and an outer one 0! the same, a second lever pivotally mounted between said central portion and the second outer one of said portions, an equalizing lever link-connected atone end to one end or said first mentioned lever and at its opposite end to the opposite end of said second mentioned lever, and draw-bars pivotally connected to the remaining ends of said two first mentioned levers and intermediate to the ends of said equalizing lever.

6. A stress equalizing device including a sup-. port having spaced apart substantially parallel bearing portions, a pair of companion levers one of said first mentioned levers and at its opposite end to the opposite end of the other of said first mentioned levers, and draw-bars pivotally connected to the remaining ends of said first mentioned levers and intermediate to the ends of said equalizing lever.

7.-A stress equalizing device including a support ihaving spaced apart substantially parallel bearing portions, a pair of companion levers placed side by side and extending through the space between said bearing portions and pivotally mounted thereon, an equalizing lever diagonally positioned with respect to said first mentioned levers and link-connected at one end to one end of one of said first mentioned levers and at its opposite end to theopposite end of the other of said first mentioned levers, draw-bars pivotally connected to the remaining ends of said first mentioned levers and intermediate to ,the ends of said equalizing lever, a singletree pivotally attached to each 01' said draw-bars, and a cable pivotally attached to each end of each of said singletrees.

8. A stress equalizing device including a plurality of parallel draw-bars, trunnion blocks each having an opening through which one of said blocks, said singletrees being arranged in sub-.

stantially parallel but partially staggered relation, a trunnion block carried by each end of each singletree, a cable terminal passing through an opening in each of said last mentioned trunnion blocks, and lock nuts threaded on each of said cable terminals above and below said trunnion blocks. i

9. A stressequalizing device including a trunnion block, a draw-bar extending through an opening therein, lock nuts threaded on said drawbar at each side of said block, a singletree pivotally mounted on said trunnion block, a trunnion block carried on each 'end of 'said singletree, cable terminals each extending through an opening in one of said last mentioned trunnion blocks, and lock nuts threaded on said terminals at each side of said blocks.

10. A stress equalizing device incdluding a trunnion block, a draw-bar extending through an opening therein, lock nuts threaded on said drawbar at each side of said block, a singletree pivotally mounted on saidtrunnion block, and a cable pivotally attached to each end of said singletree.

- Y JOSEPH E. EVANS. 

